WO 2009/021974 A2 discloses a realtime controller for industrial communication using the Ethernet communication standard and EtherCAT data packets or EtherCAT frames. The automation appliance is connected to an Ethernet data network as a field bus via a microprocessor. The communication with field devices connected to the input/output modules is effected via a local bus using EtherCAT data packets. To speed up the communication, two EtherCAT data frames are provided for the local bus, with one data frame being provided only for the data sent from the automation appliance to the input/output modules and another data frame being provided only for the data sent from the input/output modules to the automation appliance (field bus controller).
DE 100 06 265 B4 discloses an apparatus for controlling the data interchange by a communication subscriber in a serial master/slave communication system. The apparatus can be flexibly adjusted to suit communication requirements by virtue of the apparatus being set up to replace predetermined communication data. This allows a communication subscriber to actively engage in the communication data flow. In this way, communication subscribers, i.e. input/output modules, can communicate with one another without an automation appliance as master.
Against this background, it is an object of the present invention to provide an improved automation appliance which allows accelerated data transmission between a field bus and a local data bus.